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African elephants ( Loxodonta africana ) are capable of visibly altering the structure of vegetation through their browsing habits, and such alteration of habitat may be magnified when the broader movements of elephants are restricted by fences. I assessed the structure and composition of the woody and succulent components of Albany thicket vegetation at 10 fenced sites in the Eastern Cape Province, South Africa – five with elephants present, paired with five where elephants were absent. Contrary to expectations, woody and succulent thicket vegetation was structurally similar across the 10 sites, despite the vegetation at the non-elephant sites being slightly taller, denser and more complex than the sites with elephants. Woody plant community composition was also similar across the 10 sites and elephant-induced damage to woody and succulent plants was generally low. Combined, these findings support the idea that at least the woody component of thicket vegetation is generally resilient to the browsing effects of indigenous browsers such as elephants. However, it is also possible that Albany thicket vegetation at the five elephant sites may not have been exposed to elephants for long enough for elephant browsing effects to manifest. Thus, I recommend continued monitoring of elephant browsing in fenced reserves within the Thicket Biome to establish how overall vegetation structure and composition may change over time, and with increases in elephant densities. [ABSTRACT FROM AUTHOR]

Summary: Objectives: Investigations of the erosive potential of soft drinks are usually performed at room or body temperature, but drinks are more frequently served chilled, with ice, or hot. Since the rate of chemical reactions usually increases with temperature, it is predicted that erosion is more severe at high temperatures and reduced at low temperatures. The aim of this study was to investigate the correlation between enamel softening, enamel erosion, and temperature. Methods: Atomic force microscopy nanoindentation and non-contact optical profilometry were used to assess changes in enamel nanomechanical properties after 5min and erosive material loss after 30min exposure to two different non-carbonated soft drinks at 4, 25, 50 and 75°C. Results: For one drink (Robinson''s Original™ Juice Drink), there was a statistically significant difference between nanomechanical properties and erosion depth at all temperatures, with softening and erosion increasing with temperature. For another drink (Ribena ToothKind™ Juice Drink), there was a slight softening and virtually no material loss, and temperature had no statistically significant impact on erosion. There was a good linear correlation (R 2=0.94) between nanomechanical properties and material loss. Conclusions: The difference between the drinks can be explained by their composition. For the erosive drink, material loss increased, and nanohardness decreased, approximately linearly with temperature. The correlation between softening and erosion demonstrated that nanomechanical properties after very short erosion times can be considered a good predictor of bulk material loss after considerably longer erosion times. [Copyright &y& Elsevier]

Objective. Previous studies demonstrated that a non-carbonated blackcurrant juice drink with added calcium produced little erosion of enamel in vitro and in situ by comparison with other low pH fruit drinks. The aim of this study is to evaluate the erosive effects in situ of an experimental formulation carbonated drink with added calcium, compared to a conventional carbonated drink over a 20 day period using a similar design as in previous studies.Method. The study was a single centre, single blind, randomised placebo controlled three cell crossover design involving 15 volunteers. The test drinks were an experimental carbonated ready-to-drink (RTD) blackcurrant drink, a conventional carbonated RTD orange drink and water. Two enamel samples were retained in situ, in the midline of the hard palate on an upper removable acrylic appliance. Drinks were 250 ml volumes consumed four times per day during 20 working days. Measurements of enamel loss were made on enamel samples after days 2, 5, 10, 15 and 20 by profilometry.Results. The experimental carbonated blackcurrant drink caused significantly less enamel loss than the conventional carbonated orange drink at all time points measured, but was not significantly different from water at days 2, 5 and 20.Conclusions. This study has shown that it is possible to modify carbonated soft drinks in a manner similarly shown with non-carbonated soft drinks, to minimise dental erosion. [Copyright &y& Elsevier]

Objectives. To determine the in vitro erosive potential and in situ erosive effect of two new formulation low calorie carbonated orange drinks with that of two conventional diet products and water.Methods. In the in vitro study, six specimens of deciduous and permanent enamel were randomly allocated to each of the five products and a ‘4 h’ protocol employed. In the in situ study, 15 healthy volunteers participated in a single centre, single blind, 5-phase crossover study, conducted according to Good Clinical Practice, and employing a validated model.Results. The in vitro erosive potential of the experimental formulations was less than that of the comparators at all time points. Conversely, the observed erosive potential of both experimental formulations was greater than that of the control. Consistent statistically significant differences were found in relation to permanent enamel only. Unfortunately, the in situ study did not produce results entirely consistent with those of the in vitro study. Notably, a generally progressive loss of enamel was observed in specimens exposed to the control.Conclusions. The data from the in vitro study show the experimental formulations to have low comparative erosivity. However, the methodologies in vitro and in situ somewhat unusually do not correlate in ranking the erosivity of drinks. The results of this study should therefore be viewed with caution, further research being clearly warranted. [Copyright &y& Elsevier]

Objective. The aim of the study was to measure the erosive potential of a prototype sports drink on enamel in a model in situ.Methods. The study was a single centre, single blind, randomised crossover design balanced for residual effects involving 18 subjects. The drinks were the prototype formulation containing calcium and maltodextrin (test), two sports drink products containing sugars (drink with calcium and positive control) and water (negative control). During each 15-day study period, subjects wore a palatal removable appliance carrying two flat human enamel specimens. Drinks were imbibed as 250 ml volumes over 10 min 4 times per day. Loss of enamel was measured on days 5, 10 and 15 using a contacting profilometer.Results. Very little erosion occurred with the test, drink with calcium and negative control drinks and differences between the test and negative control only reached significance at day 15. The positive control produced progressive erosion over time and significantly more than the test or negative control at all time points.Conclusion. The technology of adding calcium with appropriate pH adjustment, which has been applied previously to soft and carbonated drinks to markedly reduce erosive potential, can be applied to sports drinks to the same end. Significant variation in the carbohydrate composition does not influence this outcome. [Copyright &y& Elsevier]